You are here

Phaseolus vulgaris

Dry Bean are high in starch, protein and dietary fiber, as well as being an excellent source of iron, potassium, selenium, molybdenum, thiamine, vitamin B6 and folate. Dry beans take longer to cook then most pulses, although cooking time can be shortened by soaking dried beans before cooking. Dry Bean is a highly variable species with growth habits ranging from bush varieties growing 20-60cm tall to vine varieties growing 2-3m long. While dry bean varieties range in growth habit all have characteristic green or purple alternate leaves and long pods containing 4-6 kidney-shaped seeds.

Pre-breeding

Genetic variability underlies all breeding efforts. Sometimes you have to go outside the primary genepool to find increased levels of variability. Tepary bean (Phaseolus acutifolius) is known to contain genes for traits of interest to common bean breeders such as disease resistance, increased micronutrients, and tolerance to abiotic stress (heat, cold, drought). Interspecies hybridization between tepary and common bean has led to the development of introgression lines which are being assessed for various traits. Lines with interesting phenotypes may be used as parents in the regular breeding program.

Genetics

Post harvest darkening (PHD) is a phenomenon that occurs in seed coats during storage under less than ideal conditions (heat, humidity and light). PHD is controlled by at least two unlinked but epistatic genes: J and SD. All jj plants have non-darkening seeds; JJsdsd plants have slow-darkening seeds and JJSDSD plants have regular darkening seeds (Elsadr et al. 2011. Theor. Appl. Genet. DOI 10.1007/s00122-011-1683-8).

SNP marker development: 454-based sequencing of multiple genotypes has led to the development of a 768-SNP GoldenGate assay for P. vulgaris and another for P. acutifolius that is being used to genotype various populations.

Stone seeds, which are seeds that do not absorb water, are considered a negative seed quality characteristic because they need to be removed before commercial processing. A high physical dormancy at the end of seed development is found to be the cause of this issue, but it is not known how or when it develops. This project will focus on attempting to determine when the seeds begin to develop physical dormancy, and also how to avoid hard seededness through harvest times.

As production of the dry bean is moving towards short season growing regions such as Alberta and Saskatchewan, it is becoming increasingly important to find a way to develop abiotic stress tolerances for the dry bean. Through the incorporation of genes from other species, the stress tolerance capabilities of the dry bean will increase, making it less sensitive to its surrounding climate. The tepary bean was decided upon as the best genetic donor for improvement to the dry bean, and is now being evaluated in Saskatchewan and its international partners.

This group is involved in a wide range of biotechnology projects that accelerate the legume breeding process. Double-haploid technology has been achieved in both chickpea and field pea by the CDC group in collaboration with colleagues in France and Australia. Efforts are underway to adapt this technology to lentil. Improving efficiency and integrating these techniques into routine breeding programs to enhance genetic gain are important long-term goals.

This Phaseolus vulgaris assembly for the Andean line G19833 was made available by Phytozome as a PRE-RELEASE and has been deprecated in favour of the newest published. This pre-release assembly was used in our Common Bean 454 SNP Discovery Project to anchor the reads for SNP calling and is made available here simply to provide context for that analysis. The main assembly was generated using Newbler version 2.5.3. This is an improved preliminary release of Phaseolus vulgaris that uses all of the ARRA generated data (DOE-JGI, ARRA, and USDA-ARS funding).

The nutritional value of pea, lentil, chickpea and dry bean grains are highly important for human health. Biofortification, enriching the nutritional contribution of staple crops through plant breeding, is one option that is now widely discussed in the fields of nutrition and public health at the national and international levels.

Eight germplasm were chosen for this project:CDC WM-2, BAT 93, Expresso, Higuera-E, Jalo EEP-558, PI 430219, SMARC1N-PN1, and W6-15578. Tissue was collected from multiple plants at various developmental stages for RNA extraction which led to the generation of 3'-anchored cDNA libraries using the method described in Parkin et al., 2010. Each line was sequenced using the Roche 454 Titanium sequencing protocol. Sequencing reads were aligned directly to the Phaseolus vulgaris genomic build v0.9 using GMap. Then loci which were polymorphic between at least two of the lines were identified resulting in 133,108 SNPs. All SNPs were re-mapped to the published genome assembly 1.0 (Phytozome.org; Schmutz et al. 2014).